Placenta donors to be screened for brain disease

Under pressure from the French health authorities, the pharmaceuticals
company Pasteur Merieux has decided to begin screening donors of placentas,
from which it manufactures certain blood products.

The decision follows revelations that hundreds of French children treated
with growth hormones extracted from dead bodies risk developing the fatal
brain disorder Creutzfeldt-Jakob disease. By last December the US had reported
10 cases of children who had developed CJD after receiving growth hormone
extracted from the pituitary glands of cadavers. France has uncovered
almost 30 so far.

Pasteur Merieux, a subsidiary of the giant multinational Rhone-Poulenc,
collects placentas from 44 countries, including developing countries in
Asia and South and Central America and former eastern bloc countries. The
screening is intended to allay fears that the agent that causes CJD could
be present in placentas.

Since 1967, Pasteur Merieux has been extracting the blood protein albumin
from placentas. Albumin helps to control the volume of plasma in the circulatory
system and is used in particular to treat shock. Pasteur Merieux has about
8 per cent of the world market for albumin. It is the only company to use
placentas – about 7 million a year – for this purpose. The protein can also
be made directly from plasma.

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The company says it will ask all its potential donors if they have
ever been treated with growth hormone or have a family history of CJD.

Pasteur Merieux says that only two of the countries from which it gathers
placentas – France and the US – have reported cases of CJD caused by treatment
with contaminated human growth hormone.

Dominique Dormont, a biologist at the Atomic Energy Commission (CEA)
who studies CJD, says that nothing is known about the risk of transmitting
CJD through either blood or placenta. The agent that causes the disease
has yet to be identified, but like the related agents that cause scrapie
in sheep and BSE in cattle, it is not destroyed by the normal processes
of sterilisation. Sheep can contract scrapie from placentas, which contaminate
grass after lambing and may be consumed by other animals.

Dormont says that Japanese researchers have described one case of a
woman who was diagnosed with CJD during pregnancy. When extracts from her
placenta were injected into mice, they developed signs of the disease. But
he cautions that the results have not yet been reproduced.

According to Dormont, tissue from the brain, ganglion, thymus, spleen,
parts of the intestine, bone marrow and white blood cells could cause infection.
But he says blood is far less infectious than tissue from the nervous system.

Last August, Britain stopped the company collecting placentas because
it does not test them for any infection, including HIV. But Jean-Michel
Rouzioux, director-general of Pasteur Merieux, says: ‘We have never had
a case of infection of any kind from placenta-derived albumin.’ The finished
albumin product has never been licensed in Britain and Switzerland banned
it in 1990.